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1.
Cell Host Microbe ; 32(7): 1114-1128.e10, 2024 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-38955187

RESUMEN

Plant immune homeostasis is achieved through a balanced immune activation and suppression, enabling effective defense while averting autoimmunity. In Arabidopsis, disrupting a mitogen-activated protein (MAP) kinase cascade triggers nucleotide-binding leucine-rich-repeat (NLR) SUPPRESSOR OF mkk1/2 2 (SUMM2)-mediated autoimmunity. Through an RNAi screen, we identify PUB5, a putative plant U-box E3 ligase, as a critical regulator of SUMM2-mediated autoimmunity. In contrast to typical E3 ligases, PUB5 stabilizes CRCK3, a calmodulin-binding receptor-like cytoplasmic kinase involved in SUMM2 activation. A closely related E3 ligase, PUB44, functions oppositely with PUB5 to degrade CRCK3 through monoubiquitylation and internalization. Furthermore, CRCK3, highly expressed in roots and conserved across plant species, confers resistance to Fusarium oxysporum, a devastating soil-borne fungal pathogen, in both Arabidopsis and cotton. These findings demonstrate the antagonistic role of an E3 ligase pair in fine-tuning kinase proteostasis for the regulation of NLR-mediated autoimmunity and highlight the function of autoimmune activators in governing plant root immunity against fungal pathogens.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Autoinmunidad , Resistencia a la Enfermedad , Fusarium , Enfermedades de las Plantas , Inmunidad de la Planta , Ubiquitina-Proteína Ligasas , Arabidopsis/inmunología , Arabidopsis/microbiología , Arabidopsis/genética , Ubiquitina-Proteína Ligasas/metabolismo , Ubiquitina-Proteína Ligasas/genética , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Enfermedades de las Plantas/microbiología , Enfermedades de las Plantas/inmunología , Fusarium/inmunología , Proteínas NLR/metabolismo , Proteínas NLR/genética , Regulación de la Expresión Génica de las Plantas , Ubiquitinación , Proteínas Portadoras
2.
J Bone Miner Metab ; 2024 May 16.
Artículo en Inglés | MEDLINE | ID: mdl-38755327

RESUMEN

INTRODUCTION: Bone homeostasis depends on the regulation of ß-catenin in osteoblasts. Glucocorticoids (GCs) are known to diminish ß-catenin activity via Wnt pathway signaling, leading to osteoporosis. Conversely, activating ß-catenin in osteoblasts through mitogen-activated protein kinase kinase kinase 2 (Mekk2) offers an innovative approach to combat GC-induced osteoporosis (GIOP). Fufang Zhenshu Tiaozhi (FTZ) capsules have shown effectiveness in treating GIOP, but the mechanisms behind this are still unclear. MATERIALS AND METHODS: In this study, Mekk2 knockout mice (Mekk2-/-) was generated by CRISPR/Cas9. These mice were then subjected to Alcian Blue-Alizarin Red staining and immunofluorescence to assess their bone and cartilage development. To establish models of GIOP, both Mekk2-/- and wild-type (WT) mice were treated with dexamethasone (DXMS) and subsequently given FTZ capsules. We analyzed the resulting phenotypic changes in these mice using Micro-CT scans and histomorphological studies. Primary osteoblasts, isolated from both Mekk2-/- and WT mice, underwent qRT-PCR to measure key osteogenesis markers, including Runx2, Sp7, Bgalp, Col1a1 and Alp. Cells were then exposed to treatments with either FTZ or Wnt3a and the phosphorylation levels of ß-catenin and Mekk2, along with the protein expression of Runx2, were evaluated using Western blotting and immunoprecipitation. Additionally, C3H10T1/2 cells transfected with TOPflash-luciferase and Renilla luciferase reporters were treated with FTZ and Wnt3a to measure ß-catenin activity. RESULTS: In our study, administering FTZ in vivo effectively prevented bone loss typically induced by GCs. However, it's important to note that this protective effect was substantially reduced in mice lacking Mekk2. Additionally, FTZ showed a significant ability to enhance osteogenic differentiation in primary osteoblasts, doing so by altering the expression of Mekk2. Intriguingly, the impact of FTZ on Mekk2 appears to function through a pathway separate from the traditional Wnt signaling route. Furthermore, our findings indicate that FTZ also promotes the deubiquitination of ß-catenin, contributing further to its positive effects on bone health. CONCLUSIONS: This study suggests that FTZ plays a significant role in protecting bone mass in cases of GIOP. The mechanism through which FTZ confers this benefit involves the activation of Mekk2/ß-catenin signaling pathways, which represents a promising alternative strategy to counteract the deleterious effects of GIOP by augmenting osteoblastogenesis.

3.
Front Endocrinol (Lausanne) ; 14: 1257298, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38027135

RESUMEN

Objective: Eleutheroside E (EE) is an anti-inflammatory natural compound derived from the edible medicinal herb Acanthopanax senticosus. This study aims to investigate the underlying mechanism of the anti-osteoporosis action of EE through network pharmacology, molecular docking and gut microbiota. Materials and methods: Network pharmacology was used to explore the potential core targets and main pathways mediated by EE in osteoporosis (OP) treatment. Molecular docking was exploited to investigate the interactions between the active anti-OP compounds in EE and the potential downstream targets. Following the multi-approach bioinformatics analysis, ovariectomy (OVX) model was also established to investigate the in vivo anti-OP effects of EE. Results: The top 10 core targets in PPI network were TP53, AKT1, JUN, CTNNB1, STAT3, HIF1A, EP300, CREB1, IL1B and ESR1. Molecular docking results that the binding energy of target proteins and the active compounds was approximately between -5.0 and -7.0 kcal/mol, which EE has the lowest docking binding energy with HIF1A. Enrichment analysis of GO and KEGG pathways of target proteins indicated that EE treatment could potentially alter numerous biological processes and cellular pathways. In vivo experiments demonstrated the protective effect of EE treatment against accelerated bone loss, where reduced serum levels of TRAP, CTX, TNF-α, LPS, and IL-6 and increased bone volume and serum levels of P1NP were observed in EE-treated mice. In addition, changes in gut microbiota were spotted by 16S rRNA gene sequencing, showing that EE treatment increased the relative abundance of Lactobacillus and decreased the relative abundance of Clostridiaceae. Conclusion: In summary, these findings suggested that the characteristics of multi-target and multi-pathway of EE against OP. In vivo, EE prevents the onset of OP by regulating gut microbiota and inflammatory response and is therefore a potential OP drug.


Asunto(s)
Microbioma Gastrointestinal , Osteoporosis , Femenino , Animales , Ratones , Simulación del Acoplamiento Molecular , Osteoclastos , ARN Ribosómico 16S , Osteoporosis/tratamiento farmacológico , Osteoporosis/genética
4.
J Environ Manage ; 344: 118430, 2023 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-37348300

RESUMEN

In this study, an environmentally friendly alternative was developed using catalytic ozonation by sludge-derived biochar loaded with bimetallic Fe/Ce (O3/SBC-FeCe) for enhanced sludge dewatering. The results indicated that the lowest capillary suction time (CST) of 20.9 s and water content of dewatered sludge cake (Wc) of 64.09% were achieved under the dosage of 40 mg O3/g dry solids (DS) and 0.4 g SBC-FeCe/g DS which were considered as the optimum condition. In view of excellent electron exchanging capacity of SBC-FeCe with rich Lewis acid sites and conversions of valence sates of Fe and Ce, more O3 were decomposed into reactive oxygen species under the catalytic action of SBC-FeCe, which strengthened oxidizing capacity. Enhanced oxidation rendered sludge cells inactivation and compact network structure rupture releasing intracellular water and organic substances. Subsequently, hydrophilic organic matters were attacked and eliminated lessening sludge viscosity and colloidal forces and intensifying hydrophobicity and flowability. In addition, changes of sludge morphology suggested that sludge roughness was alleviated, structural strength and compressibility were raised and porous and retiform structure was constructed providing channels for water outflow by adding skeleton builder of SBC-FeCe. Overall, the synergistic interaction of strengthened oxidation and skeleton construction improved sludge dewaterability.


Asunto(s)
Ozono , Aguas del Alcantarillado , Aguas del Alcantarillado/química , Eliminación de Residuos Líquidos/métodos , Oxidación-Reducción , Agua
5.
Materials (Basel) ; 16(8)2023 Apr 13.
Artículo en Inglés | MEDLINE | ID: mdl-37109908

RESUMEN

The widely used simple cubic-centered (SCC) model structure has limitations in handling diagonal loading and accurately representing Poisson's ratio. Therefore, the objective of this study is to develop a set of modeling procedures for granular material discrete element models (DEM) with high efficiency, low cost, reliable accuracy, and wide application. The new modeling procedures use coarse aggregate templates from an aggregate database to improve simulation accuracy and use geometry information from the random generation method to create virtual specimens. The hexagonal close-packed (HCP) structure, which has advantages in simulating shear failure and Poisson's ratio, was employed instead of the SCC structure. The corresponding mechanical calculation for contact micro-parameters was then derived and verified through simple stiffness/bond tests and complete indirect tensile (IDT) tests of a set of asphalt mixture specimens. The results showed that (1) a new set of modeling procedures using the hexagonal close-packed (HCP) structure was proposed and was proved to be effective, (2) micro-parameters of the DEM models were transit form material macro-parameters based on a set of equations that were derived based on basic configuration and mechanism of discrete element theories, and (3) that the results from IDT tests prove that the new approach to determining model micro-parameters based on mechanical calculation is reliable. This new approach may enable a wider and deeper application of the HCP structure DEM models in the research of granular material.

6.
Materials (Basel) ; 16(5)2023 Feb 24.
Artículo en Inglés | MEDLINE | ID: mdl-36902990

RESUMEN

Dry-processed rubberized asphalt mixture has recently attracted a lot of attention as an alternative to conventional asphalt mixtures. Dry-processed rubberized asphalt pavement has improved the overall performance characteristics compared to the conventional asphalt road. The objective of this research is to demonstrate the reconstruction of rubberized asphalt pavement and evaluate the pavement performance of dry-processed rubberized asphalt mixture based on laboratory and field tests. The noise mitigation effect of dry-processed rubberized asphalt pavement was evaluated at the field construction sites. A prediction of pavement distresses and long-term performance was also conducted using mechanistic-empirical pavement design. In terms of experimental evaluation, the dynamic modulus was estimated using materials test system (MTS) equipment, the low-temperature crack resistance was characterized by the fracture energy from the indirect tensile strength test (IDT), and the asphalt aging was assessed with the rolling thin-film oven (RTFO) test and the pressure aging vessel (PAV) test. The rheology properties of asphalt were estimated by a dynamic shear rheometer (DSR). Based on the test results: (1) The dry-processed rubberized asphalt mixture presented better resistance to cracking, as the fracture energy was enhanced by 29-50% compared to that of conventional hot mix asphalt (HMA); and (2) the high-temperature anti-rutting performance of the rubberized pavement increased. The dynamic modulus increased up to 19%. The findings of the noise test showed that at different vehicle speeds, the rubberized asphalt pavement greatly reduced the noise level by 2-3 dB. The pavement M-E (mechanistic-empirical) design-predicted distress illustrated that the rubberized asphalt pavement could reduce the IRI, rutting, and bottom-up fatigue-cracking distress based on a comparison of prediction results. To sum up, the dry-processed rubber-modified asphalt pavement has better pavement performance compared to the conventional asphalt pavement.

7.
Materials (Basel) ; 16(6)2023 Mar 21.
Artículo en Inglés | MEDLINE | ID: mdl-36984369

RESUMEN

Fatigue cracking is a common form of flexible pavement distress, which generally starts and spreads through bitumen. To address this issue, self-healing elastomer (SHE) modified bitumens were elaborated to assess whether these novel materials can overcome the neat asphalt (NA) fatigue performance and whether the current failure definition, failure criterion, and fatigue-restoration criteria can fit their performance. All bitumens were subjected to short-term and long-term aging. Linear amplitude sweep (LAS) test, LAS with rest period (LASH), and simplified viscoelastic-continuum-damage (S-VECD) model were utilized to appraise the behavior of the mentioned bitumens. The results showed that maximum stored pseudo-strain energy (PSE) and tau (τ) × N (number of loading cycles) failure definitions exhibited high efficiency to accommodate the fatigue life of NA and SHE-modified bitumens. Both failure criteria identified that SHE-modified bitumen (containing 1% of SHE) showed the highest increment of fatigue performance (67.1%) concerning NA. The failure criterion based on total released PSE, in terms of the area under the released PSE curve, was the only failure concept with high efficiency (R2 up to 0.999) to predict asphalt binder fatigue life. As well, the current framework to evaluate bitumen self-restoration failed to fully accommodate asphalt binder behavior, because bitumen with higher restoration could not exhibit greater fatigue performance. Consequently, a new procedure to assess this property including fatigue behavior was proposed, showing consistent results, and confirming that SHE-modified bitumen (containing 1% of SHE) exhibited the highest increment of fatigue performance (154.02%) after application of the rest period. Hence, the optimum SHE content in NA was 1%. Furthermore, it was found that a greater number of loading cycles to failure (Nf) did not ensure better fatigue performance and stored PSE influenced the bitumen fatigue behavior.

8.
Polymers (Basel) ; 14(23)2022 Nov 24.
Artículo en Inglés | MEDLINE | ID: mdl-36501491

RESUMEN

With the continuous development of road construction and maintenance, SBS(Styrene-butadiene-styrene)-modified asphalt is widely used. However, there is no mature method for restoring aged SBS-modified asphalt. This study proposes the use of SBR(polymerized styrene butadiene rubber) and bio-oil for the restoration of aged SBS. In this study, five kinds of recycled asphalt were prepared by adding 5% bio-oil, 10% bio-oil, 6% SBR, 6% SBR + 5% bio-oil, and 6% SBR + 10% bio-oil to long-term aged SBS-modified asphalt. Softening point, penetration, and rotational viscosity experiments were tested to evaluate the conventional properties. Rheological tests revealed the performance of asphalt. Fourier transform infrared spectroscopy (FTIR), and atomic force microscope (AFM) tests were tested to demonstrate the microscopic characteristics of asphalt. Conventional tests investigated that aged asphalt viscosity will increase. Bio-oil could well recycle the asphalt viscosity. SBR could also soften aged asphalt, but its modification effect is limited compared with bio-oil. Rheological tests presented that the SBR and bio-oil have little impact on the temperature sensitivity of SBS-modified asphalt. SBR and bio-oil could decrease the asphalt stiffness. However, SBR and bio-oil could ameliorate the anti-cracking behavior of aged asphalt. The microscopic tests exhibited that SBR and bio-oil could decrease the asphaltene and colloid. Meanwhile, bio-oil could supplement alcohols and ethers at wave number 1000 cm-1-1270 cm-1. Alcohols and ethers are hard to oxidize, something which has a beneficial role in the anti-aged of recycled asphalt.

9.
Materials (Basel) ; 15(24)2022 Dec 07.
Artículo en Inglés | MEDLINE | ID: mdl-36556515

RESUMEN

Innovative sustainable techniques for transportation infrastructure enhancement have been proposed in recent decades [...].

10.
Water Res ; 225: 119134, 2022 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-36182672

RESUMEN

The bismuth oxide (Bi2O3) based chloride (Cl-) removal method is one of the chemical precipitation methods possessing good selectivity and high removal efficiency of Cl- ions, but Bi2O3 often appears in the powder form, which is difficult to be recovered for regeneration. In this work, the combination of 3D printing technology and the Bi2O3 method was explored to construct the resin model including the Bi-precursors. In the optimum carbonization process at 400 °C for 30 min, the Bi3+ ions of the Bi-precursor were reduced into the metallic Bi0 nanoparticles, whose surfaces were covered by the thin Bi2O3 layers to form the heterostructured Bi0/Bi2O3 core/shell nanoparticles with an average size of 43 nm. These Bi0/Bi2O3 nanoparticles were tightly adhered to the internal and external surfaces of the hierarchical porous carbon model (Bi-PCM), which greatly facilitated their regeneration and ensured the stable Cl- removal performance. After five cycles of Cl- removal, the chloride removal efficiency over the multiple Bi-PCMs in the dark and pH 1 conditions maintained at about 26%, which then largely increased to 63.6% with UV light irradiation. The light-enhanced mechanism was related to the improved release rate of Bi3+ ions caused by photocorrosion and the Cl• radicals produced from the holes and the •OH and O2•- radicals, which quickly reacted with Bi2O3 to form BiOCl. The construction of Bi-PCMs by using 3D printing technology provides a very promising strategy for the removal of Cl- ions from wastewater.


Asunto(s)
Bismuto , Aguas Residuales , Cloruros , Carbono , Porosidad , Polvos , Halógenos , Impresión Tridimensional , Tecnología
11.
Water Res ; 220: 118704, 2022 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-35667172

RESUMEN

Sludge dewatering is an essential process for reduction of sludge volume to decrease cost of ultimate disposal. In this study, a novel method using activated carbon (AC) strengthening electrochemical (EC) treatment (EC/AC) was adopted to improve greatly sludge dewaterability. It was shown that capillary suction time (CST) and water content of dewatered sludge cake (Wc) were reduced to 55.9 ± 1.24 s and 64.3 ± 1.23%, respectively, under the optimal conditions of EC voltage 20 V, EC time 30 min and 0.2 g/g dry solid (DS) AC. AC with rich functional groups as "the third electrode" intensified electrooxidation by forming multiple microelectrodes and electron transfer capacity and conductivity of sludge were strengthened by AC in EC system, which were illustrated by electrochemical analysis. It could be found that zeta potential and particle size were increased and surface roughness was reduced after EC/AC treatment intensifying sludge hydrophobicity. Form the results of rheological behaviors of sludge, flowability was strengthened and viscosity was weakened under the conditioning of EC/AC. Besides, colloidal force and gel-like network strength were lessened, which was also verified by organic matters and percentage of inviable cells. At the same time, intracellular matters were released and degraded and bound water was released converting into free water. In addition, sludge compressibility and structural strength were increased and porous structure was formed facilitating water outflow via addition of mesoporous AC as skeleton builder, which eventually led to an improved separation efficiency of solid-water and sludge dewaterability. The results of heavy metals suggested that sludge cake after EC/AC treatment was favorable for land application.


Asunto(s)
Carbón Orgánico , Aguas del Alcantarillado , Interacciones Hidrofóbicas e Hidrofílicas , Oxidación-Reducción , Aguas del Alcantarillado/química , Eliminación de Residuos Líquidos/métodos , Agua/química
12.
J Environ Manage ; 315: 115146, 2022 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-35504185

RESUMEN

Dewatering is the basic procedure of sludge treatment and disposal, and environmentally friendly and efficient sludge conditioning methods are urgently needed. Polyhexamethylene biguanide (PHMB), a broad-spectrum germicide used in daily life and medicine, was proposed as a sludge conditioning reagent in this paper, and its effect on waste activated sludge (WAS) dewaterability was studied for the first time. Results showed that PHMB can improve sludge dewatering performance, and capillary suction time (CST) and water content (Wc) of dewatered sludge cake was reduced by 78.11% and 13.37% with 100 mg PHMB/g dry sludge (DS). Further investigation revealed that the sludge properties changed pronouncedly after PHMB conditioning, the bound water content decreased from 1.58 g/g DS to 1.29 g/g DS, the particle size (D50) increased from 34.3 µm to 39.2 µm, the zeta potential increased from -20.96 mV to -3.36 mV, and the flowability increased whilst the viscosity decreased. When the dose of PHMB was lower than 50 mg/g DS, it mainly reacted with extracellular polymeric substance (EPS), resulting in a decrease in its content, which was also manifested by the decrease of molecular weights. However, when the dose reached 100 mg/g DS, PHMB would disrupt the cytomembranes of microorganisms and release cellular contents, reflected by a corresponding growth of EPS contents and the intensity of Fourier transform infrared (FTIR) spectrum. And the scanning electron microscope (SEM) images showed that PHMB conditioning made cracks and holes on sludge microstructures. The key mechanism of PHMB improving sludge dewaterability was inferred as "organic molecules disrupting" and "sludge particles flocculating". These findings demonstrate that PHMB is promising to be a novel, effective, and environmentally friendly sludge conditioning reagent.


Asunto(s)
Matriz Extracelular de Sustancias Poliméricas , Aguas del Alcantarillado , Tamaño de la Partícula , Aguas del Alcantarillado/química , Eliminación de Residuos Líquidos/métodos , Agua/química
13.
Essays Biochem ; 66(5): 447-458, 2022 09 30.
Artículo en Inglés | MEDLINE | ID: mdl-35383834

RESUMEN

Perception of non-self molecules known as microbe-associated molecular patterns (MAMPs) by host pattern recognition receptors (PRRs) activates plant pattern-triggered immunity (PTI). Pathogen infections often trigger the release of modified-self molecules, termed damage- or danger-associated molecular patterns (DAMPs), which modulate MAMP-triggered signaling to shape the frontline of plant immune responses against infections. In the context of advances in identifying MAMPs and DAMPs, cognate receptors, and their signaling, here, we focus on the most recent breakthroughs in understanding the perception and role of non-self and modified-self patterns. We highlight the commonalities and differences of MAMPs from diverse microbes, insects, and parasitic plants, as well as the production and perception of DAMPs upon infections. We discuss the interplay between MAMPs and DAMPs for emerging themes of the mutual potentiation and attenuation of PTI signaling upon MAMP and DAMP perception during infections.


Asunto(s)
Inmunidad de la Planta , Receptores de Reconocimiento de Patrones , Inmunidad de la Planta/fisiología , Plantas , Transducción de Señal
14.
Materials (Basel) ; 15(4)2022 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-35207928

RESUMEN

The aim of the research is to quantify the property of asphalt mortar and asphalt mixture containing municipal solid waste incineration (MSWI) fly ash. The potential of partially replacing mineral fillers with MSWI fly ash in asphalt mixture production was investigated. Five different MSWI fly ash replacement ratios, which include 0%, 25%, 50%, 75%, and 100%, were adopted to assess the influence of fly ash dosage, and the optimum fly ash replacement ratio was proposed. The rheological characteristics of asphalt mortar with MSWI fly ash were assessed with the dynamic shear rheometer (DSR) and bending beam rheometer (BBR). The high temperature properties of the mixture with MSWI fly ash were assessed with the Marshall stability test and the rutting test. The low temperature cracking property was determined with the indirect tensile strength test at low temperatures. The moisture stability property was identified with the immersed Marshall test and the freeze-thaw cycles conditioned indirect tensile strength test. Based on the test results, the addition of fly ash and mineral filler remarkably increased the ǀG*ǀ of the asphalt mortar. The δ of asphalt decreased as the dosage of fly ash and mineral filler increased. The addition of fly ash and mineral filler degraded the low temperature characteristics of the mortar. Fly ash improved the high temperature characteristics of the asphalt mixture. The asphalt mixture with MSWI fly ash was more susceptible to thermal cracking than the control sample. The addition of fly ash weakened the moisture stability of the asphalt mixture. In order to guarantee the low temperature characteristics and the moisture susceptibility of the asphalt mixture, the fly ash replacement ratio was recommended to be set around 25%. With proper mixture design and fly ash dosage, the asphalt mixture would have adequate performance, as well as reduced environmental impact.

15.
Sci Rep ; 12(1): 2744, 2022 Feb 17.
Artículo en Inglés | MEDLINE | ID: mdl-35177780

RESUMEN

Aiming at the difficulty in extracting the features of time-frequency images for the recognition of car engine sounds, we propose a method to recognize them based on a deformable feature map residual network. A deformable feature map residual block includes offset and convolutional layers. The offset layers shift the pixels of the input feature map. The shifted feature map is superimposed on the feature map extracted by the convolutional layers through shortcut connections to concentrate the network to the sampling in the region of interest, and to transmit the information of the offset feature map to the lower network. Then, a deformable convolution residual network is designed, and the features extracted through this network are fused with the Mel frequency cepstral coefficients of car engine sounds. After recalibration by the squeeze and excitation block, the fused results are fed into the fully connected layer for classification. Experiments on a car engine sound dataset show that the accuracy of the proposed method is 84.28%. Compared with the existing state-of-the-art methods, in terms of the accuracy of recognizing car engine sounds under various operating conditions, the proposed method represents an improvement over the method based on dictionary learning and a convolutional neural network.

16.
Sci Total Environ ; 819: 152015, 2022 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-34843792

RESUMEN

Simultaneous removal of polycyclic aromatic hydrocarbons (PAHs) in the process of enhancement of sludge dewaterability via oxidation of hydroxyl radicals (•OH) and flocculation of Fe3+ by Fe2+-catalyzing O3 were investigated as a novel research focus. The results showed that capillary suction time (CST) and water content of dewatered sludge cake (Wc) were reduced from 57.9 s and 85.1% to 13.6 s and 69.65% under the optimum usage of 60 mg/g dry solids (DS) O3 and 80 mg/g DS FeSO4, respectively. The relevant dewatering mechanism of Fe2+-catalyzing O3 treatment was elucidated. It was found that extracellular polymeric substances-bound (EPS-bound) and intracellular water was dramatically released through destroying sludge cells and EPS gel-like structure by produced •OH. In addition, the results of X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR) and 13C NMR spectroscopy revealed that •OH oxidized and mineralized hydrophilic organic matters intensifying hydrophobicity of sludge surface. Moreover, Fe3+ generated by oxidation of Fe2+ agglomerated fragmented fine particles into large aggregates and decreased exposure of hydrophilic sites by neutralizing negative charge, which promoted water-solids separation. Meanwhile, sludge surface roughness was decreased which was determined by material type upright confocal laser microscope (CLM). As a consequence, •OH and Fe3+ were mainly responsible for enhancement of sludge dewaterability. Moreover, more than 40% of removal rate of PAHs was accomplished by Fe2+-catalyzed O3 treatment mitigating the environmental risks of PAHs spread.


Asunto(s)
Hidrocarburos Policíclicos Aromáticos , Aguas del Alcantarillado , Matriz Extracelular de Sustancias Poliméricas , Oxidación-Reducción , Aguas del Alcantarillado/química , Eliminación de Residuos Líquidos/métodos , Agua/química
17.
Sci Total Environ ; 807(Pt 3): 151025, 2022 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-34662606

RESUMEN

Dewatering treatment is an essential step to diminish sludge volume, cut down transportation costs, and improve subsequent disposal efficiency. In this study, ozone-peroxymonosulfate (O3/PMS) oxidation process was employed to ameliorate sludge dewaterability. Sludge capillary suction time (CST) and water content (Wc) of dewatered sludge cake could reduce from 70.5 s and 81.93% to 26.7 s and 65.65%, respectively, under the optimal dosage of 30 mg/g TS O3 and 0.4 mmol/g TS PMS. The increased sludge zeta potential, particle size, and fluidity promoted sludge dewatering performance apparently. The decreased hydrophilic, fluorescent EPS components and proteins/peptides-like + Lipids percentage in EPS as well as the ratio of α-helix/(ß-sheet + random coil) of treated EPS protein secondary structure was greatly responsible for the enhanced sludge dewaterability. SO4- and OH were detected in ozone-peroxymonosulfate process to crack sludge flocs, eliminate hydrophilic substances and liberate bound water. Moreover, the concentrations of both heavy metals and polycyclic aromatic hydrocarbons (PAHs) of sludge after O3/PMS conditioning were decreased, and the stability and toxicity of heavy metals were also reduced, except Zn. In conclusion, this work offered a comprehensive insight based on ozone-peroxymonosulfate (O3/PMS) advanced oxidation for improving the sludge dewaterability and environmental implication.


Asunto(s)
Ozono , Hidrocarburos Policíclicos Aromáticos , Peróxidos , Aguas del Alcantarillado
18.
J Environ Manage ; 296: 113204, 2021 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-34243089

RESUMEN

Fe2+-activated persulfate process has been introduced into sludge conditioning currently, however the key sludge properties characteristics are worthwhile comprehensively considering for the engineering implementation and management. The results indicated that both the optimal dosages of persulfate and Fe2+ were 0.6 mmol/gTS for sludge dewaterability amelioration, and the reduction efficiencies of capillary suction time (CST), specific resistance of filtration (SRF), and water content (Wc) of dewatered sludge cake reached to 90.5%, 97.2%, and 22.4%, respectively. Significantly, the persulfate and Fe2+ exerted distinctive roles in the conditioning process. The increased persulfate could promote the oxidatively disintegrated effect on sludge flocs, rendering the decrease of particle size. With the oxidative decomposition of the negatively charged biopolymers, sludge zeta potential rose gradually. However, Fe2+ contributed to more persulfate activation to generate free radicals, and the produced Fe3+ could further electrically neutralize the broken sludge fragments. The core mechanism of Fe2+-activated persulfate conditioning is "destroying and re-building" of sludge flocs. Noteworthily, EPS protein was oxidatively degraded more preferentially than EPS polysaccharide, and the decrease of the α-helix content of EPS protein was conducive to the enhancement of sludge dewaterability. Furthermore, the hydrophilic functional groups reduced clearly and element chemical states on sludge flocs altered pronouncedly, also the destroyed structure and microchannel facilitated the flowability of water. These findings provide theoretical and technical support for the practical engineering implementation of the Fe2+-activated persulfate conditioning process.


Asunto(s)
Filtración , Aguas del Alcantarillado , Biopolímeros , Oxidación-Reducción , Agua
19.
J Environ Manage ; 297: 113342, 2021 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-34314959

RESUMEN

Sludge dewatering, as one of the most important steps of sludge treatment, can facilitate transportation and improve disposal efficiency by reducing the volume of sludge. This study investigated the effects of electrolysis-activated persulfate oxidation on improving sludge dewaterability. The results indicated that the sludge capillary suction time (CST) and water content of dewatered sludge cake (Wc) reduced from 93.7 s and 87.8% to 9.7 s and 68.3% respectively at the optimized process parameters: electrolysis voltage of 40 V, electrolysis time of 20 min, and 1.2 mmol/g TS S2O82-. Correlation analysis revealed that the enhancement of sludge dewaterability was closely associated with the increased floc size and zeta potential, decreased protein content in three-layers extracellular polymeric substances (EPS) and viscosity (R = -0.868, p = 0.002; R = -0.703, p = 0.035; R ≥ 0.961, p < 0.001; R = 0.949, p < 0.001). Four protein fluorescence regions in EPS were analyzed by three-dimensional excitation-emission matrix parallel factor (3D-EEM-PARAFAC). The protein secondary structure was changed after the treatment, and the reduction of α-helix/(ß-sheet + random coil) indicated that more hydrophobic sites were exposed. Analysis by X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR) and rheological test demonstrated that the hydrophilic functional groups of the sludge were decreased and the sludge mobility was significantly enhanced after the treatment with electrolysis-activated persulfate oxidation. Moreover, bound water was converted to free water during SO4·- and ·OH generated by electrolysis-activated persulfate degraded EPS and attacked sludge cells. Meanwhile, scanning electron microscopy (SEM) images revealed that the treated sludge formed porous channel structures, which promoted the flowability of the water. These findings provide a new insight based on electrolysis-activated persulfate oxidation in sludge treatment for enhancing sludge dewaterability.


Asunto(s)
Electrólisis , Aguas del Alcantarillado , Oxidación-Reducción , Viscosidad , Eliminación de Residuos Líquidos , Agua
20.
Materials (Basel) ; 14(8)2021 Apr 18.
Artículo en Inglés | MEDLINE | ID: mdl-33919543

RESUMEN

Cold in-place recycling (CIR) asphalt mixtures are an attractive eco-friendly method for rehabilitating asphalt pavement. However, the on-site CIR asphalt mixture generally has a high air void because of the moisture content during construction, and the moisture susceptibility is vital for estimating the road service life. Therefore, the main purpose of this research is to characterize the effect of moisture on the high-temperature and low-temperature performance of a CIR asphalt mixture to predict CIR pavement distress based on a mechanistic-empirical (M-E) pavement design. Moisture conditioning was simulated by the moisture-induced stress tester (MIST). The moisture susceptibility performance of the CIR asphalt mixture (pre-mist and post-mist) was estimated by a dynamic modulus test and a disk-shaped compact tension (DCT) test. In addition, the standard solvent extraction test was used to obtain the reclaimed asphalt pavement (RAP) and CIR asphalt. Asphalt binder performance, including higher temperature and medium temperature performance, was evaluated by dynamic shear rheometer (DSR) equipment and low-temperature properties were estimated by the asphalt binder cracking device (ABCD). Then the predicted pavement distresses were estimated based on the pavement M-E design method. The experimental results revealed that (1) DCT and dynamic modulus tests are sensitive to moisture conditioning. The dynamic modulus decreased by 13% to 43% at various temperatures and frequencies, and the low-temperature cracking energy decreased by 20%. (2) RAP asphalt incorporated with asphalt emulsion decreased the high-temperature rutting resistance but improved the low-temperature anti-cracking and the fatigue life. The M-E design results showed that the RAP incorporated with asphalt emulsion reduced the international roughness index (IRI) and AC bottom-up fatigue predictions, while increasing the total rutting and AC rutting predictions. The moisture damage in the CIR pavement layer also did not significantly affect the predicted distress with low traffic volume. In summary, the implementation of CIR technology in the project improved low-temperature cracking and fatigue performance in the asphalt pavement. Meanwhile, the moisture damage of the CIR asphalt mixture accelerated high-temperature rutting and low-temperature cracking, but it may be acceptable when used for low-volume roads.

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